Combining the Cinnabar Moth (Tyria jacobaeae) and the Ragwort Flea Beetle (Longitarsus jacobaeae) for Control of Ragwort (Senecio jacobaea): An Experimental Analysis

1992 ◽  
Vol 29 (3) ◽  
pp. 589 ◽  
Author(s):  
R. R. James ◽  
P. B. McEvoy ◽  
C. S. Cox
Author(s):  
K. Betteridge ◽  
D. Costall

In spite of ragwort flea beetle (RFB) being present on a Dannevirke dairy farm, pastures were sprayed each winter to reduce ragwort density and limit the risk of ragwort poisoning of stock. The trial on this farm from June 1999 - October 2001, aimed to determine whether herbicide (H) impacted on RFB and how H and RFB each impacted on ragwort growth and persistence. RFBfree areas were created by spraying with insecticide (I). Effects of ragwort on animal health are also reported. High ester 2,4-D (H) boom-sprayed once only, in June 1999, killed most ragwort plants and reduced RFB larvae densities to low levels before the plants died. Once new ragwort established in treatment H, the plants became infested with RFB larvae. RFB larvae were suppressed by I resulting in ragwort density declining more slowly than in treatments where RFB were not suppressed. Insecticide treatments were stopped after 15 months and, at 24 months, ragwort could not be found within the trial area. Ragwort control was attributed to the cessation of herbicide spraying allowing the RFB population to reach a sufficient density to kill both small and large ragwort plants. Sub-clinical ragwort poisoning was found in livers of culled cows that had grazed on ragwort-dense pastures. Keywords: animal health, biological control, Longitarsus jacobaeae, pyrrolizidine alkaloids, ragwort, ragwort flea beetle, Senecio jacobaea


1975 ◽  
Vol 107 (9) ◽  
pp. 913-917 ◽  
Author(s):  
P. Harris ◽  
A. T. S. Wilkinson ◽  
M. E. Neary ◽  
L. S. Thompson ◽  
D. Finnamore

AbstractThe cinnabar moth, Tyria jacobaeae L., was established in the Atlantic provinces and British Columbia for the control of tansy ragwort. Establishment was difficult to obtain with imported stock: only two of 14 colonies survived, one on each coast. The rate of survival in these colonies increased with succeeding generations, and with stock from the regional colony eight of nine releases became established in Nova Scotia. Most of the established colonies increased until the ragwort was defoliated.


Oikos ◽  
1989 ◽  
Vol 54 (3) ◽  
pp. 337 ◽  
Author(s):  
Ed van der Meijden ◽  
Agnes M. van Zoelen ◽  
Leo L. Soldaat

2011 ◽  
Vol 4 (3) ◽  
pp. 332-340 ◽  
Author(s):  
Kimberly K. Crider

AbstractQuantification of interference with biological control agents can provide support for anecdotal claims of success or failure of agent establishment and efficacy. This study was initiated because of observed predation of cinnabar moth larvae by carpenter ants when releasing larvae for the control of tansy ragwort, an invasive plant in Montana. Biotic and abiotic factors were compared among three sites with historically variable moth population establishment. Two experiments were developed to (1) observe and document insect activity, predation, or disappearance on tansy ragwort stems either protected or accessible to ants; and (2) quantify the effects of ant exclusion on herbivory of tansy ragwort. Site comparisons indicated that ant colony density was highest at the driest of three sites, and, interestingly, no ant colonies were detected at the site with higher observed numbers of moth larvae and adults and lower densities of tansy ragwort. Available substrate (logs and stumps) for ant colonization did not differ between the three sites. In the ant exclusion experiments, a larger number of larvae were missing on plants accessible to ants (63%) compared with plants where ants were excluded (39%) after 36 h. Direct observation of predation of larvae by carpenter ants accounted for 9% of missing larvae on stems accessible to ants. Larvae were able to consume 81% of original flowers or buds on ant-excluded stems, compared with 18% consumption on ant-accessible stems, suggesting that ant predation could limit the efficacy of cinnabar moth larvae. These results provide one of many possible explanations for the anecdotal observations of large, persistent populations of cinnabar moths in moist areas. This work emphasizes the importance of post-release observation and monitoring to detect and, ideally, quantify factors to support anecdotal perceptions regarding the fate and subsequent efficacy of insect biological-control agents.


1990 ◽  
Vol 45 (11-12) ◽  
pp. 1185-1192 ◽  
Author(s):  
Adelheid Ehmke ◽  
Ludger Witte ◽  
Andreas Biller ◽  
Thomas Hartmann

Larvae of the arctiid moth Tyria jacobaeae reared on Senecio jacobaea or S. vulgaris take up and store pyrrolizidine alkaloids (PAs) from their host plants. Individual PAs are taken up without preference. The PA patterns found in the insect bodies correspond to the PA composi­tion of their host plants. Like plants the insects store PAs as N-oxides, and larvae as well as pupae are specifically able to N -oxidize any tertiary PA. Callimorphine (O9-(2-methyl-2-acetoxybutanoyl)-retronecine), an insect PA well known from several arctiids, was found in pupae and imagines of Tyria which as larvae had been fed on S. jacobaea. It is accompanied by small amounts of its isomer O7-(2-methyl-2-acetoxybutanoyl)-retronecine named isocallimor-phine. The callimorphines may well account for 45% of total PAs found in the insect. Only small amounts of callimorphine were detected in pupae of Tyria which as larvae had been fed on S. vulgaris. [14C]Callimorphine N -oxide was isolated and identified from Tyria pupae which as larvae received [14C]retronecine. It is suggested that Tyria is able to esterify retronecine, derived from hydrolysis of ingested plant PAs with a necic acid produced by the insect. During metamorphosis the formation of callimorphine is restricted to the early stage of pupa­tion.


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